Anderson Cooper has hit back at critics skewering Anne Hathaway over her Oscars speech and last-minute dress switch.

The actress has been tangled in controversy for days after she swapped her Valentino gown for a pink Prada confection.

So-called "Hatha-Haters" also attacked the actress for rambling through her thank-yous after receiving the best supporting actress award for her role in Les Misérables and later crying in the pressroom.

The American television personality came to her defence on his afternoon talk show Anderson Live.

He insisted few people understand the pressure Anne is under in the spotlight.

"In our morning meeting today, we were talking about this and the level of hatred people have towards Anne Hathaway; I had no idea. She seems like a perfectly lovely person," Cooper said, adding that he was "upset" by the commentary.

The CNN news anchor went on to profess his admiration for Hathaway's talent.

Cooper's co-host chimed in, calling her Oscar speech "terrible".

But he insisted the 30-year-old movie star deserves more credit.

"She seems like a lovely person, I think she's been through a lot. People have all these judgments about her; they don't know what she's really like," he said.

"She got up there, she made eye contact, she remembered people's names without reading it. I mean, give her a break."

Cooper admitted he doesn't know Hathaway personally.

But the idea of others swinging at her seems unfair, he said.

"I had no idea this whole hatred existed, I feel like I've just woken up and realised the entire universe is attacking her and I feel bad for her and I am defending her," he explained.

Cooper isn't the only one who has come to Hathaway's defence in the wake of the controversy.

Girls creator and star Lena Dunham took aim at her critics earlier this week while trying to inject some humour into the matter.

"Ladies: Anne Hathaway is a feminist and she has amazing teeth," Dunham mused on Twitter.

"Let's save our bad attitudes for the ones who aren't advancing the cause."